The overall objectives of the project are to produce an interactive computer control system for a Theratron 80 Cobalt 60 radiation therapy machine based on efficient computer programs and system capabilities which include: (1) automatic patient set up, (2) record keeping of selected treatment details, (3) monitoring of treatment procedures and (4) moving beam treatments. Goals set for the current year (1976-77) are: (1) improve the computer control algorithms for moving the Theratron precisely in time and space to execute desired prespecified movements, (2) detailed and in depth safety analyses of the present system composed of operator, patient, machine, computer, interfaces and computer programs, and (3) selection of feasible movement paths through formal optimization techniques. BIBLIOGRAPHIC REFERENCES: Kreifeldt, J.G., Kiel, R., Richichi, F., "Fundamental Aspects of Computerized Collision Detection For Radiotherapy Machines in the Treatment of Cancer." Proc. 3rd Annual New England Bioengineering Conference, Tufts University, Medford, Ma., May 9-10 1975. Kreifeldt, J.G., Hsieh, D., "Collision Avoidance Programming For Computer Control of Radiotherapy Treatment", Proc. 2nd Annual New England Bioengineering Conference, Worcester, Ma., March 29-30, 1974.